Power generating means such as gas turbine engines, generate power by passing air through a compressor, burning some of the compressed air with fuel in a combustion chamber, and expelling the resulting gases to atmosphere via a turbine system. The operation becomes self sustaining, in that the turbine system drives shafting to which a rotor or rotors are connected, the or each of which has a plurality of compressor blades spaced about its rim in known manner, for the purpose of compressing the air which flows therethrough, to the combustion chamber.
It is known, to connect a rotor to a shaft, via a drive arm consisting of an annular member, the axial cross sectional shape of which likens a hairpin, which is a term of art. However, such a shape as is described immediately hereinbefore, when absorbing the stresses imposed on the assembly of rotor and shafting during rotation, does so in a manner which results in a non uniform distribution of those stresses, which in turn, results in high value peak stress loads in local places. This adversely affects the life of the components of the assembly. Therefore, the present invention seeks to provide an improved rotor shaft connector.
According to the present invention, a rotor and shaft connector comprises an annular drive arm for interconnecting said rotor and said shaft, a radially outer portion of said drive arm being fixable to said rotor and a radially inner portion of said drive arm and being fixable to said shaft, so that said rotor and shaft are operationally maintained in radially spaced apart relationship, said drive arm including a portion that is so configured as to be semi-toroidal in configuration to define a radially outer rim of said drive arm that is fixable to said rotor, said drive arm additionally including a radially inner flange that is fixable to a corresponding flange provided on said shaft, the arrangement being such that variation in stress distribution throughout said drive arm is minimized with consequent reduction in the magnitude of stress peaks therein.